Power semiconductor component, compensation component, power transistor, and method for producing power semiconductor components

ABSTRACT

A reverse-blocking power semiconductor component includes a drift path subdivided into a source-side area and a drain-side area by a region with opposite doping. Provided above this region is a gate. Alternatively, the body zone of the one conduction type is subdivided into a source-side part and a drain-side part by a region of the other conduction type. This region acts as an electron collector. The reverse-blocking power semiconductor component can be incorporated in compensation components, and power transistors. Methods for producing power semiconductor components are also provided.

BACKGROUND OF THE INVENTION

[0001] Field of the Invention

[0002] The present invention relates to power semiconductor components,compensation components, power transistors, and methods for producingpower semiconductor components. The power semiconductor component has adrift path of a first conduction type disposed between two electrodesand to a method of producing these power semiconductor components.

[0003] Power transistors, such as DMOS transistors, UMOS or trenchtransistors, and similar semiconductor elements necessarily contain intheir structure a “reverse diode” composed of a body region (also calleda channel region) and a drain region. In numerous applications, thisreverse diode is regularly operated in the flow direction, for example,as a freewheeling diode.

[0004] In the case of a reverse diode operated in the flow direction, acurrent flows through the MOS transistor in the reverse direction. Thiscurrent in the reverse direction is not a channel current but a diodecurrent associated with a high flood of charge carriers.

[0005] If the power transistor previously operated in the reverse orblocking direction is then switched over to the forward direction, thenit absorbs voltage in the forward direction. For this purpose, thecharge carriers specifically stored in the drift path of the powertransistor have to be extracted from the semiconductor body of the powertransistor. This process entails a high reverse diode current. Here, thereverse diode current adds to the load current of the power transistorand, in this application, leads to increased switching losses, forexample in a second transistor which has to carry the entire currentwhen it is turned on.

[0006] In compensation components like those described in U.S. Pat. No.4,754,310 issued to Coe, the peak value of the reverse current (i.e.,“the reverse current peak”) is very high. A high reverse current peak isalready accompanied by problems. In addition, the reverse current incompensation components returns to zero very suddenly and “breaks down”.Break down necessarily includes stray inductances that can lead todangerous overvoltage peaks.

[0007] Previously, in order to avoid the above difficulties, a Schottkydiode has been connected in antiparallel with the power transistor. TheSchottky diode has a lower threshold voltage than the pn-reverse diodeof the power transistor. Accordingly, the Schottky diode can accept thereverse current if the Schottky diode has a sufficiently-small, overallforward voltage drop. However, this is barely possible, especially inthe case of higher-value blocking semiconductor components, because theSchottky diode would require the same blocking ability as, for example,a power transistor.

[0008] A further, previously considered possibility for overcoming theabove difficulties with power transistors is not to connect its body orchannel region to the source contact. This allows the pn-junctionbetween source region and body region to absorb the necessaryreverse-blocking voltage.

[0009] In such a power transistor having a body region that is floatingand not connected to the source contact is that, in the forwarddirection between collector and emitter with an open base, onedisadvantage is preventing the breakdown of a parasitic npn-(or pnp-)transistor composed of the source region, the body region, and the drainregion must be prevented. This is extremely difficult and complicated intechnological terms. One possibility is to minimize the gain of thisparasitic transistor with an inlaid recombination zone, for example, afloating metal or silicide contact. However, in such a case, the gainremains high in an interspace between such a recombination zone and thegate of the power transistor. For this reason, the interspace should beconfigured to be as small as possible, in order to prevent breakdown ofthe parasitic transistor (called the U_(CEO) breakdown).

[0010] If the body region is not connected to the source contact, thenit is not at a fixed potential. The turn-on voltage of the powertransistor via the substrate control effect therefore depends on thedrain-source voltage applied. In addition, a breakdown must be preventedbetween collector and emitter with open base of a parasitic npn-(orpnp-) transistor composed of the source region, the body region, and thedrain region, which is difficult in technological terms.

[0011] U.S. Pat. No. 5,202,750 issued to Gough discloses an emitterswitched thyristor, specifically an EST, as it is called, in which, ann-doped emitter region can be connected to the cathode or isolated fromthe latter via an MOS channel. This thyristor has on its rear, a p-dopedregion that acts as a p-doped emitter. This structure can switch off thethyristor, which has a very high conductivity as a result of chargecarrier flooding with minority charge carriers and majority chargecarriers, by driving the MOS channel via the associated gate.

SUMMARY OF THE INVENTION

[0012] It is accordingly an object of the invention to provide a powersemiconductor component, a compensation component, a power transistor,and a method for producing power semiconductor components that overcomethe hereinafore-mentioned disadvantages of the heretofore-known devicesof this general type and that specifically provide a reverse-blockingpower semiconductor component that, in the reverse direction, has ablocking capacity of at least a few volts, so that in the presence of avoltage in the reverse direction, no reverse diode current flows throughthe semiconductor component. In addition, the method of producing such areverse-blocking power semiconductor component is to be specified.

[0013] With the foregoing and other objects in view, there is provided,in accordance with the invention, a reverse-blocking power semiconductorcomponent. The reverse-blocking power component includes two electrodes,a drift path, a region, and a gate. The drift path of a first conductiontype is disposed in an area between the two electrodes. The region isdisposed in the drift path and subdividing the drift path into twoareas. The region is of the other conduction type, opposed to the oneconduction type. The gate is being provided with the region.

[0014] With the objects of the invention in view, there is also provideda method of producing the power semiconductor component. According tothe method, the region that subdivides the drift path is produced byepitaxy.

[0015] The power semiconductor component according to the inventionachieves its blocking capacity, which may be restricted to a few volts,in the reverse direction as a result of the fact that in the area of thedrift path, an additional region doped opposite to the drift path isprovided, so that the drift path is subdivided into two areas. Ifappropriate, more than just one such region may also be introduced intothe drift path. The drift path is then accordingly subdivided into aplurality of areas. If, for example, two regions of the other conductiontype, opposed to the conduction type of the drift path, are incorporatedinto the drift path, then there is a total of three areas, into whichthe drift path is subdivided.

[0016] In the following text, it will be assumed that the drift path isn-doped. In this case, the region inserted into the drift path isp-doped in order to subdivide it. Of course, however, the oppositeconduction type may also be present in each case. This means that inthis case a p-doped drift path is then subdivided into at least twoareas by an n-doped region.

[0017] The p-doped (or n-doped) region inserted into the n-doped (orp-doped) drift path is not connected to the source contact or the bodyregion. However, it divides the drift path into two completely mutuallyisolated areas, into n+1 areas in the case of n regions, so that atleast one pn junction blocking in the reverse direction is producedbetween the p-doped region and the n-doped area on the source side ofthe drift path. In this case, in the case of a power transistor as apower semiconductor component, it is assumed that this drain is biasednegatively with respect to its source.

[0018] Because this additional p-doped region also blocks the currentflow in the forward direction in the case of a power transistor as apower semiconductor component, a second MOS gate disposed to produce ann-conducting channel, connecting the two areas of the drift path, in theinserted region. If there is a plurality of such regions, then thesecond MOS gate must be provided over these regions, so that all theareas of the n-doped drift path are connected by the n-conductingchannel of this second MOS gate.

[0019] This second gate can be connected to the actual first gate, thatis, the normal gate of the power transistor as an example of the powersemiconductor component and in particular can be composed of its directextension.

[0020] When the power semiconductor component is operated in the forwarddirection, the second gate is switched on together with the first gate.If the power semiconductor component is operated in the blockingdirection (forward or backward), on the other hand, then both gates areswitched off.

[0021] A substantial advantage of this reverse-blocking powersemiconductor component according to the invention resides in the factthat its blocking capability in the forward direction remainsunrestricted, and no collector-emitter breakdown of a parasiticnpn-transistor composed of source, body, and drain occurs, andadditionally that the body region remains at the fixed source potential,so that the turn-on voltage of the power semiconductor component doesnot depend, via the substrate control effect, on the drain-sourcevoltage applied.

[0022] It is a second object of the present invention to provide areverse-blocking power semiconductor component in which the body regionis not connected, yet reliably prevents a U_(CEO) breakdown of theparasitic transistor composed of source region, body region, and drainregion is reliably prevented. In addition, the invention provides amethod of producing a reverse-blocking power semiconductor component.

[0023] With the objects of the invention in view, there is also provideda reverse-blocking power semiconductor component including asemiconductor body, a body zone, a source metalization, and a body zone.The semiconductor body forms a drift path of one conduction type. Thebody zone of the other conduction type, opposed to the one conductiontype, is provided in the semiconductor body. The source zone of the oneconduction type placed in the body zone and connected to the sourcemetalization. The region of the one conduction type is inlaid in thebody zone to define a source-side part and a drain-side part in the bodyzone. The region inlaid in the body zone is short-circuited at least tothe drain-side part of the body zone. The source metalization isconnected electrically only to the source zone.

[0024] In the case of the power semiconductor component according to theinvention of the second variant, the body region is not connected to thesource metalization and is therefore floating. Therefore, it achieves ablocking capability in the reverse direction that may be restricted to afew volts.

[0025] However, in the forward direction, in the case of a floating bodyregion, the breakdown voltage is reduced considerably with respect to astructure with a connected body region. The U_(CEO) breakdown of theparasitic transistor composed of source region, body region, and drainregion causes the reduction of the breakdown voltage.

[0026] The mechanism of the U_(CEO) breakdown utilizes a blockingcurrent produced in the spatial charging zone of the blocking pnjunction between body region and drain region and enlarged as a resultof avalanche generation or multiplication arrives in the body region asa hole current and therefore, as base current, drives the parasiticbipolar transistor. In turn, the parasitic bipolar transistor suppliesan electron stream that is increased by the transistor gain of theparasitic transistor. In turn, the electron stream flows through thebody region into the spatial charging zone, where avalanche generationrestarts the multiplication process.

[0027] In order then to prevent the U_(CEO) breakdown of the parasiticbipolar transistor composed of source region, body region, and drainregion in the forward direction, the feedback mechanism for themultiplication process is interrupted in accordance with the invention.

[0028] In the following explanation, it will be assumed that the driftpath of the power semiconductor component is n-doped, while the bodyregion exhibits p-doping. Of course, however, converse conduction typesare also possible.

[0029] In the body region, which in the present case is to be p-doped,an additional n-doped region (in the case of an n-doped body region, anadditional p-doped region) is inlaid. The additional n-doped region isinlaid in such a way that electrons that come from the source region donot have a continuous path in the p-doped body region as far as thespatial charging zone of the blocking pn junction between body regionand drain region. This additional region, n-doped in the present case,is connected electrically by a purely resistive or non-rectifyingconnection. Preferably, the connection includes, in particular, a metalcontact, at least to the drain-side part of the body region subdividedby the additional region. In addition, a purely resistive connection canbe disposed between the additional region and the source-side part ofthe body region.

[0030] Electrons that come from the source region, in the case of thepower semiconductor component according to the invention, areintercepted by the additional region inlaid in the body region. Becausethe pn junction is definitely short-circuited, these electrons no longercan overcome the pn junction to the drain-side part of the body regionas minority charge carriers.

[0031] In the case of the reverse-blocking power semiconductorcomponent, the blocking capability in the forward direction ismaintained unrestrictedly, because no U_(CEO) breakdown occurs.Likewise, a U_(CEO) breakdown can be prevented In the reverse direction.If the additional region inlaid in the body region is alsoshort-circuited to the source-side part of the body region.

[0032] As previously discussed, the additional region is intended to ben-doped and is inlaid in the body region. The additional regionfunctions as a collector of the respective parasitic bipolar transistorcomposed of source region, body region, and additional region in thecase of blocking loading in the forward direction or, respectively, ofdrain region, body region, and additional region in the case of blockingloading in the reverse direction, and therefore collects electrons.Therefore, diffusion of the electrons toward the blocking pn junctionbetween source region and body region is prevented.

[0033] As a result of the additional region inlaid in the body region,the feedback mechanism causing the U_(CEO) breakdown as a result ofmultiplication in the spatial charging zone and the gain of theparasitic bipolar transistor is interrupted in a straightforward manner.The additional inlaid region intercepts the electrons emitted from thesource region accomplishes this.

[0034] The invention includes a mode of operation of thereverse-blocking power transistor. An example of the reverse-blockingpower transistor may be represented as a body region that is p-doped andthe inlaid region that has the n-doping. The parasitic npn bipolartransistor composed of source region, body region, and drain region issubdivided into two series-connected npn transistors by the additionaln-doped region inlaid in the body region. Of these two npn transistors,the first transistor, composed of the inlaid n-doped region, the bodyregion, and the drain region, is operated with emitter-base shortcircuit, so that this first transistor has its full blocking capability.On the other hand, the other, second transistor composed of sourceregion, body region, and inlaid n-doped region is brought into U_(CEO)operation. Or, if the additional, inlaid n-doped region is alsoshort-circuited to the source-side part of the body region, the secondtransistor is operated as a diode in the forward direction. Therefore,the second transistor has only a low or even no blocking capability;however, it does not need any such capability.

[0035] The power semiconductor component has a blocking capability of atleast a few volts in the reverse direction, so that under a reversevoltage, no diode current flows through the power semiconductorcomponent. In this case, the current can flow readily through anantiparallel-connected pn diode or Schottky diode with appropriatecharacteristics.

[0036] The power semiconductor component according to the invention,depending on the thickness and doping of the drift path, can block inthe forward direction approximately between 30 and 1000 V. The driftpath can then have doping between about 2·10¹⁶ charge carriers/cm³ and1·10¹⁴ charge carriers/cm³, and can have a thickness of about 2 μm to100 μm.

[0037] The power semiconductor component according to the invention ispreferably a power transistor. However, the invention can also beapplied in the same way to other power semiconductor components, such asIGBTs (bipolar transistors with isolated gate) and thyristors.

[0038] The semiconductor body of the power semiconductor componentaccording to the invention is preferably composed of silicon. Instead ofsilicon, other suitable semiconductor materials, such as SiC,A_(III)B_(v) and so on can also be used.

[0039] A preferred area of application for the present invention iscompensation components, in which compensation regions of the conductiontype opposed to the conduction type of the drift path are inlaid in thelatter. The compensation regions can be floating or connected to thebody region.

[0040] The additional region inlaid in the body region can also bereferred to as an “electron collector”. This electron collector isshort-circuited at least to the drain-side part of the body zone andpreferably to the source-side part of the latter, which can be donethrough a metallic short-circuit by a metal contact or plug.

[0041] It is not necessary for there to be semiconductor material, inparticular silicon, above the metallic short circuit or metal plugbetween the body region and the inlaid, additional region. It is alsonot important precisely where the metallic short circuit or metal plugis disposed. The metallic short circuit or metal plug also can beprovided on the surface of the semiconductor body.

[0042] While, in the first variant of the power semiconductor componentaccording to the invention, the drift path is “subdivided”, in the caseof the second variant there is a “subdivision” of the body zone. Thedrift zone and body zone also can be subdivided in each case to create athird variant.

[0043] Other features which are considered as characteristic for theinvention are set forth in the appended claims.

[0044] Although the invention is illustrated and described herein asembodied in a power semiconductor component, a compensation component, apower transistor, and a method for producing power semiconductorcomponents, it is nevertheless not intended to be limited to the detailsshown, since various modifications and structural changes may be madetherein without departing from the spirit of the invention and withinthe scope and range of equivalents of the claims.

[0045] The construction and method of operation of the invention,however, together with additional objects and advantages thereof will bebest understood from the following description of specific embodimentswhen read in connection with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0046]FIG. 1 is a sectional view showing a first embodiment of a firstvariant of a planar power transistor with reverse-blocking capability;

[0047]FIG. 2 is a sectional view showing a second embodiment of thefirst variant of a reverse-blocking planar power transistor withcompensation structure;

[0048]FIG. 3 is a sectional view showing a third embodiment of the firstvariant of a trench power transistor with reverse-blocking capability;

[0049]FIG. 4 is a sectional view showing a fourth embodiment of thefirst variant of a reverse-blocking trench power transistor withcompensation structure;

[0050]FIG. 5 is a sectional view showing a fifth embodiment of the firstvariant of a reverse-blocking trench power transistor with compensationstructure;

[0051]FIG. 6 is a sectional view showing a sixth embodiment of the firstvariant of a reverse-blocking trench power transistor with compensationstructure;

[0052]FIG. 7 is a sectional view showing a seventh embodiment of thefirst variant of a reverse-blocking planar power transistor withincreased n-doping near a parasitic p-channel transistor;

[0053]FIG. 8 is a sectional view showing an eighth embodiment of thefirst variant of a reverse-blocking planar power transistor withinterrupted gate;

[0054]FIG. 9 is a sectional view showing a ninth embodiment of the firstvariant of a reverse-blocking planar power transistor with increasedinsulating layer thickness near a parasitic p-channel transistor;

[0055]FIG. 10 is a sectional view showing a tenth embodiment of thefirst variant of a reverse-blocking trench power transistor withincreased n-doping near a parasitic p-channel transistor;

[0056]FIG. 11 is a sectional view showing an eleventh embodiment of thefirst variant of a reverse-blocking power transistor in SOI technology(SOI=silicon-on-insulator);

[0057]FIG. 12 is a sectional view showing a twelfth embodiment of thefirst variant of a reverse-blocking power transistor with a buried oxidelayer;

[0058]FIGS. 13a to 13 f are sectional views showing a method forproducing the planar power transistor of the first embodiment of FIG. 1;

[0059]FIG. 14 is a sectional view showing a first embodiment of thesecond variant of a planar power transistor with reverse-blockingcapability;

[0060]FIG. 15 is a sectional view showing a second embodiment of thesecond variant of a planar power transistor with reverse-blockingcapability;

[0061]FIG. 16 is a sectional view showing a third embodiment of thesecond variant of a planar power transistor with reverse-blockingcapability;

[0062]FIGS. 17a and 17 b are sectional views showing a fourth embodimentof the second variant of a planar power transistor with reverse-blockingcapability in two planes, lying one behind the other;

[0063]FIG. 18 is a sectional view showing a fifth embodiment of thesecond variant of a reverse-blocking planar power transistor with acompensation structure;

[0064]FIG. 19 is a sectional view showing a sixth embodiment of thesecond variant of a trench power transistor with reverse-blockingcapability;

[0065]FIG. 20 is a sectional view showing a seventh embodiment of thesecond variant of a reverse-blocking trench power transistor withcompensation structure;

[0066]FIG. 21 is a sectional view showing an eighth embodiment of thesecond variant of a reverse-blocking trench power transistor withcompensation structure;

[0067]FIG. 22 is a sectional view showing a ninth embodiment of thesecond variant of a reverse-blocking trench power transistor withcompensation structure;

[0068]FIGS. 23a and 23 b are sectional views showing a tenth embodimentof the second variant of a reverse-blocking power transistor in SOItechnology (SOI=silicon-on-insulator) in two planes, lying one behindthe other;

[0069]FIGS. 24a and 24 b are sectional views showing an eleventhembodiment of the second variant of a reverse-blocking power transistorwith a buried oxide layer in two planes, lying one behind the other;

[0070]FIGS. 25 and 26 each are circuit diagrams showing areverse-blocking power transistor combination having two oppositelyswitched transistors with a common gate connection;

[0071]FIG. 27 is a sectional view showing a twelfth embodiment of thesecond variant of a reverse-blocking power transistor according to thecircuit diagram of FIG. 26; and

[0072]FIGS. 28a to 28 f are sectional views showing a twelfth exemplaryembodiment (cf. FIG. 15) of the second variant of a method formanufacturing the power transistor.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0073] In all the figures of the drawing, sub-features and integralparts that correspond to one another bear the same reference symbol ineach case.

[0074] In addition, in all the exemplary embodiments of the firstvariant of the invention (FIGS. 1-13), it will be assumed that the driftpath is n-doped, so that the region subdividing the drift path into twoareas has p-doping. Of course, dopings of the respectively oppositeconduction type are also possible here.

[0075] In addition, the invention will preferably be described usingpower transistors. However, it can be applied in the same way to otherpower semiconductor components, such as IGBTs (bipolar transistors withisolated gate), diodes, and thyristors.

[0076] Finally, in the following exemplary embodiments, thesemiconductor bodies of the individual semiconductor components are ineach case composed of silicon. Instead of silicon, however, anothersuitable semiconductor material, such as SiC, A_(III)B_(v) and so canalso be used.

[0077] Referring now to the figures of the drawings in detail and first,particularly to FIG. 1 thereof, there is shown a silicon body 1including an n⁺-doped silicon substrate 2 and an n-doped semiconductorlayer 3 provided thereon. A p-doped body zone 4 lies in thesemiconductor layer 3. The p-doped body zone 4 contains an n⁺-dopedsource zone 5.

[0078] The body zone 4 and the source zone 5 are provided with a firstmetalization 6 as a source contact, while a second metalization 7 isapplied, as a drain contact, to the surface of the silicon substrate 2.In an insulating layer 8 of silicon dioxide, for example, a gateelectrode 9 of polycrystalline silicon, for example, is embedded in theinsulating layer 8 in the area above the interspace between the sourcezone 5 and the semiconductor layer 3, that is to say in the area abovethe body zone 4.

[0079] A planar power transistor described to this extent is ofconventional construction.

[0080] According to the invention, there is now in the semiconductorlayer 3 a further p-doped region 10, which subdivides the semiconductorlayer 3 that forms a drift path into a source-side drift path 3 a and adrain-side drift path 3 b.

[0081] In the case of this planar power transistor, a reverse-blockingpn junction 11 is therefore located between the source-side drift path 3a and the region 10.

[0082] In addition, the gate electrode 9 includes two parts: a firstgate 9 a lies between the source zone 5 and the source-side part 3 a,while a second gate 9 b is placed above the region 10. Accordingly, thegate electrode can also actually include two isolated parts (9 a and 9b).

[0083] Depending on the thickness and doping of the semiconductor layerforming the drift path with its parts 3 a and 3 b, the planar powertransistor of the exemplary embodiment of FIG. 1 can block a voltage inthe forward direction approximately between 30 and 1000 V. Thedrain-side part 3 b of the drift path can have a doping between about2·10¹⁶/cm³ and 1·10⁴/cm³ and a thickness of about 2 μm to 100 μm. Thesource-side part 3 a of the drift path can have the same doping level orbe more highly doped than the drain-side part 3 b. In order not toimpair the forward blocking capability, the area charge containedbetween the p-doped areas, that is between the p-doped body zone 4 andthe p-doped region 10, must not exceed the breakdown charge, which isaround 1·10¹²/cm² in the case of silicon, in the entire area of a cell.It should be noted that the breakdown charge is linked to the breakdownvoltage via the second Maxwell equation.

[0084] Instead of the region 10, a plurality of such regions can also beinserted into the drift path: i.e., the semiconductor layer 3. Thisregion 10 is not connected to the first metalization 6, that is to saythe source contact, or the body zone 4. However, it subdivides the driftpath into the two completely mutually isolated parts 3 a and 3 b, sothat the pn junction 11 that blocks in the reverse direction (drain isnegative with respect to source here) is produced between the region 10and the source-side drift path 3 a.

[0085] Because this additional region 10 also blocks the current flow inthe forward direction, the second gate 9 b is disposed to produce ann-conducting channel, connecting the two areas 3 a, 3 b of the driftpath, in the surface area of the region 10. This second gate 9 b can beconnected to the first gate 9 a. That is, the “normal” gate of the powertransistor and, for example as shown in FIG. 1, can be composed of itsdirect extension. However, separate configuration of the two gates 9 a,9 b is also possible.

[0086] In the forward mode of the power transistor, the second gate 9 bis switched on together with the first gate 9 a, while in the blockingmode in the forward or reverse direction, both gates 9 a and 9 b remainswitched off.

[0087] A substantial advantage of the power semiconductor componentaccording to the invention resides in the fact that its blockingcapability in the forward direction is maintained unrestrictedly, sothat no breakdown occurs between collector and emitter of a parasitictransistor, and additionally in the fact that the body zone 4 is at thefixed potential of the first metalization 6, that is, source potential,so that the turn-on voltage does not depend, via the substrate controleffect, on the applied drain-source voltage of the power transistor.

[0088]FIG. 2 shows a further exemplary embodiment of the powersemiconductor component according to the invention. Here, however, asopposed to the exemplary embodiment of FIG. 1, the power transistor isprovided with a compensation structure. Therefore, in the n-dopedsemiconductor layer 3 there is at least one p-doped compensation pillar12 that is so highly doped that, in the blocking mode, the chargecarriers of the compensation pillar 12 and the charge carriers of thesemiconductor layer 3 surrounding the latter deplete one another.Otherwise, reference is made to U.S. Pat. No. 4,754,310, which waspreviously cited, for details relating to compensation components.

[0089] In FIG. 3, a trench power transistor with reverse-blockingcapability is illustrated schematically. To distinguish the embodimentsof FIGS. 1 and 2, in the embodiment of FIG. 3, the gate electrode 9 islocated in a trench 13, which is lined with a gate insulating layer 14of silicon dioxide, for example. Here, too, the uniformly shaped gateelectrode 9 can be divided into a first gate 9 a in the area of the bodyzone 4 and a second gate 9 b in the area of the region 10.

[0090] In a fourth exemplary embodiment in FIG. 4, a trench powertransistor with reverse-blocking capability is again illustrated, as inFIG. 3. However, like the exemplary embodiment of FIG. 2, this powertransistor of the exemplary embodiment of FIG. 4 has a compensationstructure. This means that there is a p-doped compensation pillar 12 inthe otherwise n-doped semiconductor layer 3 of the drift path.

[0091] Other configurations can also be selected for the compensationstructure. Exemplary embodiments of this are shown in FIGS. 5 and 6.

[0092] In the exemplary embodiment of FIG. 5, the compensation pillars12 do not adjoin the p-doped region 10, as in the exemplary embodimentof FIGS. 2 and 4. Instead, here the compensation pillars 12 are disposedlaterally “at the sides”, substantially underneath the gate electrodes9.

[0093] In the exemplary embodiment of FIG. 6, the compensation columns12 are led laterally further past the trenches 13 and reach as far asthe surface of the silicon body 1 underneath the insulating layer 8.

[0094] Still further, different configurations are possible for thecompensation structure. For example, the compensation pillars may befloating, as a whole or partially and can be connected to the region 10,as a whole or partially. Furthermore, the compensation pillars can becoherent or else individually configured on their own. In addition,instead of compensation pillars, individual p-conducting regions, whichare not coherent in DC terms, can be inlaid in the n-conducting driftpath.

[0095] The turn-on voltage of the parasitic p-channel transistorcomposed of the body zone 4, the drain-side drift path 3 a and theregion 10 (cf. FIG. 1, for example) should be increased in numerousapplications and should be at least as high as the value of the desiredreverse-blocking capability of the power transistor. Such an increase inthe turn-on voltage can be achieved with the exemplary embodiments ofFIGS. 7 to 10.

[0096] In the exemplary embodiment of FIG. 7, which otherwisecorresponds to the exemplary embodiment of FIG. 1, increased n-doping isprovided in the area of the parasitic p-channel transistor. This meansthat the surface areas of the source-side drift path 3 a, that is to saysource regions 15, are more highly doped than the rest of thesource-side drift path.

[0097] Another possible way of increasing the turn-on voltage of theparasitic p-channel transistor can be seen from the exemplary embodimentof FIG. 8: there, in the area above the source-side drift path 3 a, thegate electrode 9 is interrupted, so that here there are actually twoisolated gates 9 a and 9 b. The gate 9 a forms the actual gate of thepower transistor, while the gate 9 b, the upper, second gate, is used tosupply the two areas 3 a and 3 b of the drift path with a connectingn-conducting channel.

[0098] In the exemplary embodiment of FIG. 9, the layer thickness of theinsulating layer 8 is increased in the area of the source-side driftpath 3 a, so that here there is a thickened area 8 a. Accordingly, thegate electrode 9 in this area is provided at a greater distance from thedrift path 3 a.

[0099]FIG. 10 shows an exemplary embodiment corresponding to FIG. 3. Ina similar way to that in the exemplary embodiment of FIG. 7, FIG. 10shows that the doping of the source-side area of the drift path 3 a isincreased in regions 15 a.

[0100] The various possible ways of increasing the turn-on voltage ofthe parasitic p-channel transistor, which have been described above byusing FIGS. 7 through 10, can, if required, also be used simultaneously:for example by the first gate 9 a and the second 9 b (cf. FIG. 8), in anarea of a thicker insulating layer (cf. reference symbol 8 a in FIG. 9)being connected via the source-side area 3 a of the drift path. Thisconnection can be left out in the area of a thinner insulating layer.

[0101] The structures of power transistors explained above by usingFIGS. 1 to 10, can be implemented as configurations of strip cells,square cells, hexagonal cells, or other cell shapes. In each case, theycan be connected in parallel with one another.

[0102] A further two fundamentally further different exemplaryembodiments of the power semiconductor component according to theinvention are illustrated in FIGS. 11 and 12.

[0103] Thus, FIG. 11 shows a power transistor in SOI technology. Thepower transistor is disposed above an oxide layer 17 on a carrier wafer16 and embedded in a further oxide layer 18. Here, the drift pathincludes the source-side area 3 a and the drain-side area 3 b, which areseparated from each other by the p-doped region 10. An n⁺-dopedconnecting region 19 serves, in a similar way to the silicon substrate2, to provide good contact with the second metalization or drainelectrode 7.

[0104] Finally, the reverse-blocking power transistor of the exemplaryembodiment of FIG. 12 has a buried insulating layer of silicon dioxide,for example. The drift path of this power transistor is separated by thep-conducting region 10 into the source-side part 3 a and the drain-sidepart 3 b. In this exemplary embodiment, too, the gate electrode 9 againextends, as a first gate 9 a, over the channel of the actual powertransistor and, as a gate 9 b, over the region 10.

[0105] In the following text, a method of producing the powersemiconductor component according to the invention is to be explainedusing FIGS. 13a to 13 f.

[0106] First of all, as shown in FIG. 13a, a semiconductor body 1composed of an n⁺-doped silicon substrate 2 and an n-doped semiconductorlayer 3 deposited thereon are provided. The semiconductor layer 3 istherefore weaklier doped than the silicon substrate 2. This is followedby gate oxidization with formation of a gate insulating layer 21 ofsilicon dioxide and gate electrodes 9 of doped polycrystalline silicon,which are both structured in the usual way by etching, as shown in FIG.13a.

[0107] Then, as illustrated in FIG. 13b, the p-doped region 10separating the two areas 3 a and 3 b of the drift path are introduced byion implantation of boron, for example, which is followed by furtherimplantation of phosphorus, for example, in order to produce ann-conducting area 3 a′, from which the source-side part 3 a of the driftpath is later produced. Following outward diffusion of boron andphosphorus, the structure illustrated in FIG. 13b is therefore present.

[0108] Depending on the desired doping levels, penetration depths anddopants used, boron and phosphorus in the present example, the areas 10and 3 a′ can be produced in one order or the other or, if appropriate,also together.

[0109] Then, in the usual way, a p-doped body zone 4 is introduced byimplantation and outward diffusion of boron, for example, as a result ofwhich the structure illustrated in FIG. 13c is obtained.

[0110] By ion-implanting of phosphorus, for example, and subsequenthealing, an n⁺-doped source zone 5 is then produced. The structureillustrated in FIG. 13d is then present.

[0111] This is further followed by the deposition of an intermediateoxide to form the insulating layer 8 of silicon dioxide that sheaths thegate electrodes 9, and the etching of a contact hole, so that thestructure of FIG. 13e is present. Finally, a further metalization 6 isapplied as a source electrode in order to arrive at the structure shownin FIG. 13f and corresponding to the exemplary embodiment of FIG. 1.

[0112] During the production of the trench power transistor from theexemplary embodiment of FIG. 3 and other trench power transistors, thevarious doping regions can be produced in a manner corresponding to thatin FIG. 13 or else by a plurality of epitaxial steps. For example, it ispossible to produce the two p-conductive regions, namely the body zone 4and the region 10, firstly as a coherent region by epitaxy orimplantation and diffusion, and then to introduce the source-side part 3a of the drift path by high-energy implantation. If a slow-diffusingdopant is used for this source-side part 3 a of the drift path, such asarsenic or antimony, the implantation can even be conducted before thediffusion of the body zone 4. Finally, it is also still possible toproduce the region 10 by of high-energy implantation, for example.

[0113]FIG. 14 shows a silicon body 1 including an n⁺-doped siliconsubstrate 2 and an n-doped semiconductor layer 3 provided thereon. Inthe semiconductor layer 3 there is a p-doped body zone 4 that containsan n⁺-doped source zone 5.

[0114] The source zone 5 is provided with a first metalization 6 ofaluminum, for example, as a source contact, while a second metalization7 also of aluminum, for example, is applied as a drain contact to thesurface of the silicon substrate 2. A gate electrode 9 ofpolycrystalline silicon, for example, is embedded in an insulating layer8 of silicon dioxide, for example.

[0115] The planar power transistor described to this extent is ofconventional construction.

[0116] According to the invention, there is now in the body zone 4 afurther additional, n-doped region 10 a, which subdivides the body zoneinto a source-side part 4 a and a drain-side part 4 b.

[0117] The additional n-doped region 10 a inlaid in the body zone 4 isconnected, via a metal plug 22 of aluminum, for example, or a silicideor another suitable material, at least to the drain-side part 4 b of thebody zone 4, in a purely resistive, non-rectifying connection, and islikewise preferably also connected electrically to the source-side part4 a of the body zone 4.

[0118] In the case of this planar power transistor, there is areverse-blocking pn junction 11 between the source-side part 4 a of thebody zone 4 and the source zone 5.

[0119] The effect of the additional region 10 a that is inlaid in thebody zone 4 is that electrons that come from the source zone 5 do notfind a continuous path in the body zone 4 as far as the spatial chargingzone of the blocking pn junction between the body zone 4 and thesemiconductor layer 3 forming the drain. Electrons that come from thesource zone 5 are therefore intercepted by the region 10 a and can nolonger overcome the pn junction to the drain-side part 4 b of the bodyzone 4 as minority charge carriers, since this junction isshort-circuited by the metal plug 22.

[0120] Above the metallic short circuit resulting from the metal plug 22between the body zone 4 and the region 10 a, it is not necessary forsemiconductor material or silicon to be present. Instead, this metallicshort circuit can be displaced underneath an insulating layer 23 ofsilicon dioxide, for example, or else onto the semiconductor surfaceinto the insulating layer 8. Exemplary embodiments of this are shown inFIGS. 15 and 16. In FIG. 15, the metal plug 22 forming the metal shortcircuit is located underneath an oxide layer 23 composed of silicondioxide. In the exemplary embodiment of FIG. 16, the metallic shortcircuit has been displaced to the surface of the semiconductor body. Analuminum layer forming the metal plug 22 here produces a conductiveconnection between the source-side part 4 a of the body zone 4, theregion 10 a and the drain-side part 4 b of the body zone 4. Oneadvantage of the exemplary embodiments of FIGS. 15 and 16 is that thesecan be produced more easily, because it is simpler to produce themetallic short circuit under an oxide layer as in the exemplaryembodiment of FIG. 15, or on the semiconductor surface, as in theexemplary embodiment of FIG. 16.

[0121]FIGS. 17a and 17 b show an exemplary embodiment that is similar toFIG. 15. In the exemplary embodiment of FIG. 16, the metallic shortcircuit resulting from the metal plug 22 is displaced, for example, toone side of a strip-like power transistor, and its other side has thegate electrode 9. In the exemplary embodiment of FIGS. 17a and 17 b, thesubdivision between the metallic short circuit and gate electrode isconducted differently. Here, the gate electrode 9 is in a front (orrear) area of the strip-like power transistor, while the metallic shortcircuit resulting from the metal plug 22 is displaced to the rear (orfront) area of the power transistor.

[0122] The exemplary embodiments of FIGS. 15, 16, 17 a, and 17 bdemonstrate that the metallic short circuit between the region 10 ainlaid in the body zone 4 and dividing the latter into two parts 4 a and4 b, and at least the drain-side part 4 b of the body zone 4 can beshaped virtually as desired. It is merely essential that there is such ametallic short circuit present in any case between the inlaid region 10a and at least the drain-side part 4 b, preferably the source-side part4 a of the body zone 4.

[0123] In FIGS. 18 to 22, there are further exemplary embodiments of thepower semiconductor component according to the invention of the secondvariant, in the form of power transistors with compensation structureand/or a gate disposed in a trench (trenchgate).

[0124] In detail, FIG. 18 shows an exemplary embodiment of areverse-blocking planar power transistor with compensation structure.

[0125] This power transistor has a p-doped compensation pillar 12 inlaidin the n-doped semiconductor layer 3. This compensation pillar 12 is sohighly doped that, in the blocking mode, the charge carriers of thecompensation pillar 12 and the charge carriers of the semiconductorlayer 3 surrounding the latter cancel one another. Otherwise, inrelation to details of compensation components, reference is made toU.S. Pat. No. 4,754,310, which was previously cited.

[0126] Of course, the compensation structure of compensation componentsis not restricted to pillar-type configurations, as shown in theexemplary embodiment of FIG. 18. Instead, other embodiments ofcompensation regions are also possible. In addition, the compensationregions do not need to be connected to the body zone 4. Instead, theycan also be inlaid in a floating manner and, if appropriate, in regionsseparated from one another, in the semiconductor layer 3 forming a driftpath.

[0127]FIG. 19 shows, as a further exemplary embodiment of the powersemiconductor component according to the invention of the secondvariant, a trench power transistor in which the gate electrode 9 islocated in a trench 13 lined with an insulating layer 14 of silicondioxide, for example. In this exemplary embodiment, too, the body zone 4is subdivided by the n-doped region 10 a into a source-side part 4 a,which adjoins the source zone 5, and a drain-side part 4 b, which isadjacent to the semiconductor layer 3 forming the drain.

[0128]FIG. 20 shows an exemplary embodiment that corresponds to theexemplary embodiment of FIG. 19, but here the power transistor has acompensation structure with a compensation pillar 12. In FIG. 21, thiscompensation structure is modified: two compensation pillars 12 here arelocated substantially underneath the areas of the trenches 13 and do notadjoin the body zone 4. Finally, FIG. 22 shows an exemplary embodimentin which the compensation pillars 12 are led past the trenches 13 at thesides and reach as far as the surface of the semiconductor bodyunderneath the insulating layer 8.

[0129] The structures of power transistors explained above using FIGS.14 to 22 can be implemented as configurations of strip cells, squarecells, rectangular cells, hexagonal cells, or other cell shapes and canin each case be connected in parallel with one another.

[0130]FIGS. 23a, 23 b and 24 a, 24 b illustrate a further twofundamentally further different exemplary embodiments of the powersemiconductor component according to the invention.

[0131] Thus, FIGS. 23a and 23 b show a power transistor in SOItechnology that is disposed above a silicon dioxide layer 17 on acarrier wafer 16 and is embedded in a further insulating layer 18. Thebody zone 4 here includes the source-side part 4 a and the drain-sidepart 4 b, which are separated from each other by the n-doped region 10a. An n⁺-doped connecting region 19 is used, in a similar way to thesilicon substrate 2, to provide good contact with the secondmetalization or drain electrode 7.

[0132]FIGS. 23a and 23 b illustrate sections in various planes throughthe power transistor. The metalization 6 for the source is provided in a“front” area of the, for example, strip-like power semiconductorcomponent, while the metal plug 22, which short-circuits the region 10 ato the two parts 4 a and 4 b of the body zone 4, is placed in a “rear”area. Here, the second metalization 7 for drain is led over the entiredepth of the power transistor.

[0133] In a further reverse-blocking power transistor, shown in FIGS.24a and 24 b in two planes lying one behind the other, a buriedinsulating layer 20 of silicon dioxide, for example, is provided. Thebody zone 4 of this power transistor, as in the preceding exemplaryembodiments, includes a source-side part 4 a and a drain-side part 4 bseparated therefrom by the region 10 a. In a similar way to theembodiment of FIGS. 23a and 23 b, the gate electrode 9 is in a “frontarea” of the power transistor, while the metal plug 22 producing theshort circuit between the region 10 a, on the one hand, and thesource-side part 4 a and the drain-side part 4 b of the source zone 4,is inlaid in the insulating layer 8 in a rear area.

[0134] The power semiconductor component according to the invention mayalso be built up in structural terms by a combination of twosemiconductor chips. For this purpose, a first power MOSFET with aconventional construction (for example with compensation structure) 25,which ensures a forward blocking capability, and also a second powerMOSFET 26, which merely has to exhibit a low blocking capability, areneeded. This second MOSFET 26 achieves its reverse-blocking capabilityby being connected anti-serially in relation to the first MOSFET 25. Inthis case, the source contacts of the first and of the second MOSFET 25and 26 are connected to each other. Likewise, the two gates of theMOSFETs 25, 26 are connected together to form a common connection. Thedrain of the second transistor 26 then forms the source of the overallstructure, while the drain of the first transistor 25 constitutes thedrain of the overall structure, as shown in the circuit diagram of FIG.25.

[0135] In the turned-on state of this overall structure, the firstMOSFET 25 is operated in the first quadrant of the current/voltagecharacteristic, that is to say “normally”, while the second MOSFET 26has current flowing through it in the reverse direction, that is to sayis operated in the third quadrant.

[0136] The configuration of FIG. 25 is expediently accommodated in acommon housing, which overall needs only three connections to theoutside (source, gate, drain).

[0137] Mounting the chips in the housing side by side (“chip-by-chip”)or else on one another (“chip-on-chip”) is possible.

[0138] Depending on the desired mounting, different structures may bepreferred for the second MOSFET 26. A first example of this is aconventional vertical power MOSFET with a drain connection on the rearside and combined source/body connection on the front side. A secondexample is a lateral power MOSFET, in which the drain connection is alsoplaced on the front side. Particularly advantageous for chip-on-chipmounting is a source-down transistor, as it is known, in which gate anddrain are placed on the front side and source on the rear side.

[0139] Since the second transistor 26 needs only a low blockingcapability, it is also possible to use a power transistor without a bodyconnection: that is, with a floating body zone 4. Such a transistor canbe used in the manner described above or else conversely, the drain ofthe second transistor 26 being connected to the source of the firsttransistor 25, and the source of the second transistor 26 serving as asource for the overall structure. A reverse-blocking power transistorcombination of this type, in which the source of the transistor 25 isconnected to drain or source of the transistor 26, whose body zone isnot connected, can be seen from FIG. 26.

[0140]FIG. 27 shows a practical exemplary embodiment of the circuitaccording to FIG. 26. The gate electrodes 9 of the two transistors 25,26 are connected together. The second metalization 7 (drain) of thetransistor 26 is connected via the first metalization 6 of thetransistor 25 to the body zone 4 and the source zone 5 of the transistor25, whose second metalization 7 forms the drain of the overallstructure. The source of the overall structure is provided by the firstmetalization 6 of the transistor 26.

[0141] In the structures of FIGS. 25 to 27, the body zones 4 of the twotransistors 25, 26 in each case correspond to the parts 4 b and 4 a ofthe body zone 4 of the preceding exemplary embodiments.

[0142] In the following text, a method of producing the power transistoraccording to the exemplary embodiment of FIG. 15 will also be explained,using FIGS. 28a to 28 f.

[0143] Firstly, as shown in FIG. 28a, a semiconductor body 1 includingan n⁺-doped silicon substrate 2 and an n-doped semiconductor layer 3deposited thereon epitaxially is provided. The semiconductor layer 3 istherefore weaklier doped than the silicon substrate 2. There follows agate oxidization with formation of a gate insulating layer 21 of silicondioxide and of gate electrodes 9 of doped polycrystalline silicon, bothbeing structured in the usual way by etching, so that finally thestructure shown in FIG. 28a is obtained.

[0144] Then, as illustrated in FIG. 28b, the drain-side part 4 b of thep-doped body zone 4 and an n-doped region 24 are introduced byimplantation and outward diffusion. For the p-doping, boron, forexample, can be used, while phosphorus is suitable for the n-doping.Depending on the desired doping levels, penetration depths and dopantsused, the region of the part 4 b and the region 24 can be produced inone order or another or else together. In any case, the structure shownin FIG. 28b is therefore obtained. It should be further remarked that,in FIG. 28b and in the following FIGS. 28c to 28 f, the siliconsubstrate 2 has been left out in order to simplify the illustration.

[0145] The source-side part 4 a of the p-doped body zone 4 is thenimplanted and diffused, by which means the additional n-doped region 10a separating the parts 4 a and 4 b of the body zone 4 is also producedfrom the region 24. The structure obtained in this way is shown in FIG.28c.

[0146] Next, the source zone 5 is introduced by implanting arsenic, forexample, and by subsequent healing. In this way, the n⁺-doped sourcezone 5 is produced. The structure shown in FIG. 28d is thereforepresent.

[0147] Then, a deposition of intermediate oxide and the etching ofcontact holes and trenches through the additional n-doped region 10 a asfar as the lower part of the body zone 4 are then performed. Thisproduces the trench 13, which reaches as far as the part 4 b of the bodyzone 4. In this way, the structure shown in FIG. 28e is present.

[0148] Finally, in the trench 13, the metal plug 22 is produced andetched back as far as the upper part of the body zone 4. The insulatinglayer 23 is then formed, likewise with back-etching. As the last step,the first metalization 6 is applied. In this way, the structure shown inFIG. 28f is obtained.

[0149] In principle, the power semiconductor components of the otherexemplary embodiments can be produced in a similar way. For example, inthe exemplary embodiment of FIG. 19, the various doping regions 3, 4 b,10, 4 a, and 5 can be produced in a corresponding way or else via aplurality of epitaxial steps. Furthermore, it is possible to produce thetwo p-doped parts 4 a and 4 b of the body zone 4 initially as a coherentregion by epitaxy or implantation and diffusion and subsequently toinsert the additional n-doped region 10 a by implantation at highenergy.

[0150] If a slowly diffusing dopant, such as arsenic or antimony, isused for the additional n-doped region, then the implantation can evenbe conducted before the diffusion of the body zone 4.

[0151] Finally, it is also further possible to produce the drain-sidepart 4 b of the body zone by high-energy implantation.

[0152] In the case of the trench structures, that is to say for examplein the exemplary embodiment of FIG. 19, the production of the metal plug22 can be performed in a similar way to that in the case of the planarstructures, that is to say in the exemplary embodiment of FIG. 15. Inthe exemplary embodiments which have the metal plug 22 providing themetal short circuit at the semiconductor surface, the metal plug can beformed in a conventional way, for example by vapor deposition.

I claim:
 1. A reverse-blocking power semiconductor component,comprising: two electrodes defining an area therebetween; asemiconductor layer disposed in the area between said two electrodes,defining a drift path of a first conduction type therein; and a regiondisposed in said drift path and subdividing said drift path into twoareas, said region being of the other conduction type, opposite to theone conduction type, said region having a gate.
 2. The powersemiconductor component according to claim 1, including a further gate,said further gate being configured coherently with said gate of saidregion.
 3. The power semiconductor component according to claim 1,wherein said drift path of said semiconductor layer has a drain-sidearea, said drain-side area having a dopant concentration between 2·10¹⁶charge carriers/cm³ and 1·10¹⁴ charge carriers/cm³.
 4. The powersemiconductor component according to claim 1, wherein said drift pathhas a drain-side area, said drain-side area having a layer thickness ofabout 2 μm to 100 μm.
 5. The power semiconductor component according toclaim 1, wherein said drift path has a source-side area and a drain-sidearea, said source-side area having at least the same level of doping assaid drain-side area.
 6. The power semiconductor component according toclaim 1, wherein said drift path has a breakdown charge not beingexceeded.
 7. The power semiconductor component according to claim 6,where said breakdown charge is 1·10¹² charge carriers/cm² in silicon. 8.The power semiconductor component according to claim 1, wherein saiddrift path has a source-side area; and a parasitic MOS transistor has aturn-on voltage and a channel formed by said source-side drift path. 9.The power semiconductor component according to claim 8, wherein saidsource-side area has a part adjoining said gate of said region, and saidpart has an increased dopant concentration compared to a remainder ofsaid region.
 10. The power semiconductor component according to claim 8,including an insulating layer having a given thickness and sheathing thegate electrode, said thickness being increased in said source-side areaof said drift path.
 11. The power semiconductor component according toclaim 8, wherein said gate is not present in said source-side area ofsaid drift path.
 12. A trench power semiconductor component, comprising:two electrodes defining an area therebetween; a semiconductor layerdisposed in the area between said two electrodes, defining a drift pathof a first conduction type therein; and a region disposed in said driftpath and subdividing said drift path into two areas, said region beingof the other conduction type, opposite to the one conduction type, saidregion having a gate.
 13. The trench power semiconductor componentaccording to claim 12, wherein: said drift path has a trench formedtherein; and said gate is disposed in said trench.
 14. An SOI powersemiconductor component, comprising: two electrodes defining an areatherebetween; a semiconductor layer disposed in the area between saidtwo electrodes, defining a drift path of a first conduction typetherein; and a region disposed in said drift path and subdividing saiddrift path into two areas, said region being of the other conductiontype, opposite to the one conduction type, said region having a gate.15. The power semiconductor component according to claim 1, including aburied insulating layer in said drift path.
 16. The power semiconductorcomponent according to claim 1, wherein said region subdividing saiddrift path is p-doped.
 17. The power semiconductor component accordingto claim 16, wherein said region is doped with boron.
 18. A compensationcomponent, comprising: two electrodes defining an area therebetween; asemiconductor layer disposed in the area between said two electrodes,defining a drift path of a first conduction type therein; and a regiondisposed in said drift path and subdividing said drift path into twoareas, said region being of the other conduction type, opposite to theone conduction type, said region having a gate.
 19. The compensationcomponent according to claim 18, including: a body zone in saidsemiconductor layer; and a compensation region connected to said bodyzone.
 20. The power semiconductor component according to claim 18,wherein said compensation region is floating.
 21. The powersemiconductor component as claimed in claim 19, wherein saidcompensation region is a compensation pillar.
 22. The powersemiconductor component according to claim 1, wherein said gate of saidregion subdividing the drift path is formed from polycrystallinesilicon.
 23. A method for producing a power semiconductor component,which comprises: providing two electrodes defining an area therebetween;providing a semiconductor layer in the area between the two electrodes;defining a drift path of a first conduction type in the semiconductorlayer; providing a region in the drift path; subdividing the drift pathinto two areas, the region being of the other conduction type, oppositeto the one conduction type; providing the region with a gate; implantingthe region dividing the drift path; and allowing outward diffusion ofdopants of the other conduction type from the region.
 24. The methodaccording to claim 23, which further comprises, producing one of theareas as a source-side area of the drift path by a step selected fromthe group consisting of implanting the source-side area in the driftpath and outward diffusion epitaxy.
 25. A method for producing a powersemiconductor component, which comprises: providing two electrodesdefining an area therebetween; providing a semiconductor layer in thearea between the two electrodes; defining a drift path of a firstconduction type in the semiconductor layer; providing a region in thedrift path; subdividing the drift path into two areas, the region beingof the other conduction type, opposite to the one conduction type;providing the region with a gate; and producing the region subdividingthe drift path by epitaxy.
 26. The method according to claim 23, whichfurther comprises, producing one of the areas as a source-side area ofthe drift path by a step selected from the group consisting ofimplanting the source-side area in the drift path and outward diffusionepitaxy.
 27. A reverse-blocking power semiconductor component,comprising: a semiconductor body forming a drift path of one conductiontype; a body zone of the other conduction type, opposite to the oneconduction type, provided in said semiconductor body; a sourcemetalization; a source zone of the one conduction type placed in saidbody zone and connected to said source metalization; and a region of theone conduction type being inlaid in said body zone to define asource-side part and a drain-side part in said body zone, said regioninlaid in said body zone being short-circuited at least to saiddrain-side part of said body zone; said source metalization beingconnected electrically only to said source zone.
 28. The powersemiconductor component according to claim 25, wherein said regioninlaid in said body zone is also short-circuited to said source-sidepart of said body zone.
 29. The power semiconductor component accordingto claim 27, wherein said inlaid region is short-circuited with a purelyresistive connection.
 30. The power semiconductor component according toclaim 27, wherein said inlaid region is short-circuited with anon-rectifying connection.
 31. The power semiconductor componentaccording to claim 27, wherein said inlaid region is short-circuitedwith a metal contact.
 32. The power semiconductor component according toclaim 27, wherein said inlaid region acts as an electron collector. 33.The power semiconductor component according to claim 27, wherein saidsemiconductor body forming the drift path has a doping between 2·10¹⁶charge carriers/cm³ and 1·10¹⁴ charge carriers/cm³.
 34. The powersemiconductor component according to claim 25, wherein saidsemiconductor body forming the drift path has a thickness between 2 μmto 100 μm.
 35. The power semiconductor component according to claim 31,wherein said metal contact is disposed in said semiconductor body. 36.The power semiconductor component according to claim 31, wherein saidmetal contact is disposed on a surface of said semiconductor body. 37.The power semiconductor component according to claim 28, including acompensation structure.
 38. The power semiconductor component accordingto claim 37, wherein said compensation structure includes a compensationregion inlaid in said drift path.
 39. The power semiconductor componentaccording to claim 38, including a floating compensation pillar.
 40. Thepower semiconductor component according to claim 38, including acompensation pillar connected to said body zone.
 41. The powersemiconductor component according to claim 37, wherein said compensationstructure includes a pillar-like compensation region.
 42. The powersemiconductor component according to claim 27, wherein saidsemiconductor body has a trench formed therein; and a gate is disposedin said trench.
 43. The power semiconductor component according to claim27, including a carrier wafer; and said a semiconductor body, said bodyzone, said source metalization, said source zone, and said region areformed on said carrier wafer by SOI technology.
 44. The powersemiconductor component according to claim 27, including an insulatinglayer buried in said semiconductor body.
 45. A power semiconductorcomponent, comprising: a first chip and a second chip serially connectedto each other, each including a respective semiconductor body forming adrift path of one conduction type, a body zone of the other conductiontype, opposite to the one conduction type, provided in saidsemiconductor body, a source metalization, and a source zone of the oneconduction type placed in said body zone and connected to said sourcemetalization, a region of the one conduction type inlaid in said bodyzone to define a source-side part and a drain-side part in said bodyzone, said region inlaid in said body zone being short-circuited atleast to said drain-side part of said body zone, and said sourcemetalization being connected electrically only to said source zone. 46.The power semiconductor component as claimed in claim 45, wherein saidfirst chip and said second chip are built up jointly.
 47. The powersemiconductor component as claimed in claim 45, wherein said first chipand said second chip are mounted chip-on-chip.
 48. The powersemiconductor component according to claim 45, wherein each of saidfirst chip and said second chip has a respective MOSFET.
 49. The powersemiconductor component according to claim 48, wherein: each of saidMOSFETs has a respective gate; and said gates of said MOSFETs areconnected.
 50. The power semiconductor component according to claim 48,wherein: each of said MOSFETs has a source; and said sources of saidMOSFETs are connected to each other.
 51. The power semiconductorcomponent according to claim 27, wherein the one conduction type is then-conduction type.
 52. A power transistor, comprising: a semiconductorbody forming a drift path of one conduction type; a body zone of theother conduction type, opposite to the one conduction type, provided insaid semiconductor body; a source metalization; a source zone of the oneconduction type placed in said body zone and connected to said sourcemetalization; and a region of the one conduction type inlaid in saidbody zone to define a source-side part and a drain-side part in saidbody zone, said region inlaid in said body zone being short-circuited atleast to said drain-side part of said body zone; said sourcemetalization being connected electrically only to said source zone. 53.A method of producing a power semiconductor component, which comprises:including a semiconductor body forming a drift path of one conductiontype; providing a body zone of the other conduction type, opposite tothe one conduction type in the semiconductor body; providing a sourcemetalization; providing a source zone of the one conduction type placedin the body zone and connecting the source zone to the sourcemetalization; inlaying a region of the one conduction type in the bodyzone to define a source-side part and a drain-side part in the bodyzone; short-circuiting the region inlaid in the body zone at least tothe drain-side part of the body zone; connecting the source metalizationelectrically only to the source zone; and producing the regionsubdividing the body zone is produced by implantation and outwarddiffusion.
 54. A method of producing a power semiconductor component,which comprises: including a semiconductor body forming a drift path ofone conduction type; providing a body zone of the other conduction type,opposite to the one conduction type in the semiconductor body; providinga source metalization; providing a source zone of the one conductiontype placed in the body zone and connecting the source zone to thesource metalization; inlaying a region of the one conduction type in thebody zone to define a source-side part and a drain-side part in the bodyzone; short-circuiting the region inlaid in the body zone at least tothe drain-side part of the body zone; connecting the source metalizationelectrically only to the source zone; and producing the region thatsubdivides the body zone by epitaxy.
 55. The method as claimed in claim53, which further comprises: producing initially a body zone by epitaxy;subdividing the body zone into two parts by introducing subsequently theadditional region by high-energy implantation.
 56. The method as claimedin claim 53, which further comprises: producing initially a body zone byimplantation and diffusion; subdividing the body zone into two parts byintroducing subsequently the additional region by high-energyimplantation.
 57. The method according to claim 53, which furthercomprises implanting the additional region before the outward diffusionof the body zone.